Electronic, magnetic and elastic properties of Mo2FeB2: First-principles calculations

Abstract

The first-principles calculations are performed to investigate structure stability, magnetism, electronic structure and elastic properties of Mo2FeB2 in nonmagnetic (NM), ferromagnetic (FM) and antiferromagnetic (AF) cases. Density functional theory and ultrasoft pseudopotentials are used in this study. It is found that the lattice parameters of the AF case are more close to the experimental data than the ones of the NM and FM cases, and the AF one has the lowest energy, indicating it is the ground state. All of the cases are stable thermodynamic structures. Furthermore, the AF case expresses more stability than the FM and NM cases because it has the largest formation enthalpy value. The density of states and overlap populations are analyzed for NM, FM and AF cases of Mo2FeB2. B–B and B–Mo are covalent bonding and give the positive to shear modulus. According to the analysis of magnetism, Fe atoms play the key point. The FM and AF cases of Mo2FeB2 have a lower bulk modulus, but higher shear modulus and Young’s modulus than of the NM case. It is obvious that the spin restriction can significantly affect the moduli of Mo2FeB2, and the FM and AF cases show brittle character while the NM one ductile character.